1. Field
Exemplary embodiments of the invention relate to a thin-film transistor (“TFT”) substrate and a display device, and in particular, to a TFT substrate using an oxide semiconductor, a display device including the same, and a method of fabricating the TFT substrate.
2. Description of the Related Art
In general, a display device has a pair of electrodes, which are used to generate electric field, and an electro-optical active layer interposed therebetween. One of the pair of the electrodes is applied to an electric signal via a switching device.
In the display device, a thin-film transistor (“TFT”) may be used as the switching device. The TFT has an active layer, which is generally including amorphous silicon, but recently, as demands for large displaying area and high resolution in the display device increase, there is an increasing need for a TFT capable of providing a high performance. However, it is expected that the amorphous-silicon-based TFT technology could not realize mobility higher than 0.5 centimeters squared per volt-second (cm2/Vs).
Accordingly, several next-generation devices are being actively studied. An oxide semiconductor is receiving great attention, because it has high mobility, which ranges from several tens cm2/Vs to several hundreds cm2/Vs, is suitable for a large-area display panel, is fabricated at a low process temperature, and has low photo insensitiveness.